I checked by creating a separate rolebinding and clusterrolebindings to assign access for pipeline resources like below :
$ oc create clusterrole pipelinerole1 --verb=create,get,list,patch,delete --resource=tektonpipelines,openshiftpipelinesascodes
$ oc create clusterrole pipelinerole2 --verb=create,get,list,patch,delete --resource=repositories,pipelineruns,pipelines
$ oc adm policy add-cluster-role-to-user pipelinerole1 user1
$ oc adm policy add-role-to-user pipelinerole2 user1
However, even after assigning these rolebindings/clusterrolebinsings to the users , users are not able to see the Pipelines section.